ARM: dts: msm: Add USB dload cookie relate device node on MSM8953

Linux USB DIAG driver needs to update PID and serial number with
IMEM memory to avoid DIAG port hopping while performing RAMDUMP
collection over USB. Hence add device node entry with IMEM
driver for USB dload cookie imem start address and size.

Change-Id: I80722d4dbb5ce3459d694739837ad5b6a3437bdb
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>